Light sensitive reproduction material comprising a colloid containing an aldehyde and a diazotized phenyl amine compound and use thereof



United States Patent tion, Murray Hill, NJ.

N0 Drawing. Filed Mar. 13, 1962, Ser. No. 179, 89

Claims priority, applicatign Germany, Mar. 15, 1961, 3

34 Claims. (or. 96-49) The present invention relates to a light sensitive reproduction material comprising a support and a colloid layer which contains, as the sensitizing agent which effects tanning of the colloid under the influence of light, a mixture of a diazo compound and an aldehyde.

It is known to add bichromates, as sensitizing agents, to colloid layers for use in reproduction processes, but these layers have the great disadvantage that they can be stored for only a very brief time. High molecular weight condensation products of carbonyl compounds and diazo compounds have already been prepared, in accordance with DRP 596,731, and for the preparation of these condensatiori products, strong acids of relatively high concentration must be used, with the result that non-uniform tanning substances are obtained which, when dissolved with hardenable colloids, often possess insutiicient shelflife and tanning qualities. In particular, layers produced on metal supports with such solutions have a storageability which is insufficient for practical purposes.

A light sensitive material has now been found which comprises a support and a colloid layer containing a diazo compound as a sensitizing substance, and in which the colloid layer contains at least one aldehyde and one or more diazo compounds of amines, corresponding to the following general formula HzN- NH-Br in which R, is an alkyl, aryl, aralkyl, cycloalkyl or a heterocyclic residue R is hydrogen, halogen, alkyl,

boxyl group, and

n is an integer from 1 to 2;

and, in addition, may contain dyestuffs and fillers.

Amines which may be used, in accordance with the general formula above, are, e.g.: p-aminodiphenylamine, 4- amino-4'-methyl diphenylarnine, 4-amino-3'-methyl-diphenylarnine, 4-amino-4-methoxy-diphenylam-ine, 4-arnino 4 chloro-diphenylamine, 4-amino-4-nitrodiphenylamine, 1-monoethylamino-Z-methylt-aminobenzene, monoethylamino-3-carboxy-4*aminobenzene, tylamino-3-chloro-4 amino-benzene, l-rnonocyclohexylamine-3-methyl-4-arninobenzene, 1-mono-2,6-dichlorobenzylamino-4-aminobenzene, and l-mono-6-ethoxy-benzthiazolylamino-4-arnino-benzene.

The amines are applied in the form of their diazotizaalkoxy, or a nitro or carl-monobution products. The diazonium chlorides, diazonium bromides, diazonium sulfates, diazonium borofiuorides and the double salts, in particular the zinc chloride double salts of the halides, are exemplary. Mixtures of such diazonium salts may also be used.

Examples of suitable aldehydes to be added to the colloid layers, in combination with the above diazo compounds, are: lower aliphatic aldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, chloroacetaldehyde,

. trichloroacetaldehyde, glyoxal, glutardialdehyde, butyrviolet light are of particular advantage.

aldehyde; also aromatic aldehydes, such as cinnamaldehyde, resorcylaldehyde, salicylaldehyde, stilbenealdehyde, and terephthaldialdehyde; and heterocyclic aldehydes, such as furfural, and pyridine-4-aldehyde. Mixtures of aldehydes may also be applied.

Suitable colloids for the light sensitive material of the present invention are, e.g.: gelatin, polyvinyl pyrrolidone, polyacrylic acid, egg albumin, casein, photographic paste and cellulose ethers; particularly suitable is polyvinyl alcohol, in admixture with polyvinyl acetate, if desired, to which plasticizers, such as dibutyl phthalate tricresyl phosphate, dioctyl phthalate, or benzylbutyl phthalate are advantageously added. Where the base is a saponifiable plastic foil, such as a cellulose acetate foil, the surface layer which forms upon saponification, e.g. the layer ofhydrate of cellulose which forms, may serve as the colloid.

Base materials which may be used as supports for the colloid layers according to the present invention are pretreated papers generally used for printing plates, plastic foils, metal supports, e.g. of aluminum, zinc, or copper, or highly porous materials, in particular fabrics or fibrous fleeces, consisting of materials such as polyamides, polyesters, polyacrylonitrile, polyvinylidene chloride, and cottori, or of metal, e.g. bronze, brass or copper.

Generally, for the preparation of the light sensitive mate'rial, the supports are coated with the colloid solution containing the diazo compound and the aldehyde. For this purpose, the solution is either applied by casting, whirling or spraying, or the material is passed through the solution, or the solution may be applied by means of rollers or brushes or by any other suitable method, and subsequently dried.

If a non-porous material is used as the support, e.g. metal or pre-treated paper, the reproduction material ac cording to the present invention may be used in known manner for the preparation of planographic printing plates. For this purpose, the material is exposed under a master, whereby the light-struck areas of the colloid layers are hardened. Subsequently, the colloid layer, in the areas which were not struck by light, is removed by a suitable solvent, in most cases water, and the tanned image thus produced is inked up with greasy ink and used for the production of prints.

If highly porous supports are used, the material according to the present invention may be advantageously used for the production of screen printing stencils.

The diazonium compounds are added to the colloid solutions in amounts ranging from about 0.1 to 6 percent by weight, preferably 0.5 to 2.5 percent; the aldehydes are added to the colloid solutions in quantities such that the molar ratio of aldehyde to diazonium compound in the range of from 1:1 to 20:1, preferably 5:1 to 10:1.

In some cases, it may be advisable to add even larger amounts of aldehyde.

In addition to the diazonium compounds and the aldehydes, the colloid solutions may contain fillers in finely distributed form. This may frequently be of advantage when the colloid solutions are to be used for screen printing. The fillers are applied in a finely divided and uniforrnly distributed form, i.e. in grain sizes of from S to 30 preferably 10 to 20 Suitable fillers are e.g. polyvinyl alcohol, polyamide, titanium' dioxide, silicon diioxide, or starch.

The, light sensitive solutions may also be colored, in which case dyestuffs which have low absorption of ultra Such dyestuffs are, e.g. Methylviolet BB (Schultz Farbstofftabellen, 7th edition, volume 1 (1931), page 327, No. 763), Rosaniline hydrochloride (Schultz Farbstoiftabellen, page 326, No.

I 762.), Sudan Blue II (Colour Index, Solvent Blue 35, vol.

II, page 2883), Sudan Red G (Colour Index, Solvent Red I, vol. II, page 2843).

The light sensitive material according to the preserit invention shows excellent tanning characteristics under the action of light. This was unexpected, since, in genera the single components, eg p-diazodiphenylamine or formaldehyde, have practically no tanning effect on colloids under the influence of light, even under conditions which favor tanning, e.g. at a relative humidity, at 40 C., of 60%. On the other hand, the addition of aldehyde will cause an improvement of the tanning action where the organic diazo compounds used have a tanning effect by themselves. Moreover, by means of this combination of diazo compounds and aldehydes, solutions may be prepared the shelf-life of which is by far superior to that of solutions prepared, e.g., with a high molecular weight condensation product. Further, it is not necessary to prepare such condensation products.

The invention will be further illustrated by reference to the following specific examples:

Example I A superficially saponified cellulose acetate foil is immersed in a solution consisting of 1 part by weight of the diazonium chloride of p-amino-diphenylamine and 2 parts by weight of a 40 percent formaldehyde solution in 100 parts by volume of water, and excess solution is removed by squeeze rollers. After drying by means of hot air, the foil is exposed under a photographic negative and then rinsed with running water. After the usual fixing of the foil with an aqueous solution of gum arabic, methyl cellulose, or dextrin, to which some phosphoric acid has been added, the foil may be used for printing on a planographic or offset machine. Positive prints are obtained.

Instead of the superficially saponified cellulose acetate foil mentioned above, there may be used, with equally good results, a paper foil provided with a hydrophilic surface, e.g. a cellulose methyl ether surface.

Instead of the diazonium chloride, the same amounts may be used of the diazonium bromide, the diazonium sulfate or the borofluoride of the p-amino-diphenylamine, the results being equivalent.

Example 11 One part by weight of the diazonium sulfate of 4-aminodiphenylamine is dissolved in 100 parts by weight of a percent solution of polyvinyl alcohol (e.g. Mowiol No. -88) and to this solution 2 parts by weight of a percent formaldehyde solution are added, with stirring, at room temperature. A polished copper plate is coated with this solution on a plate whirler. After exposure under a diapositive, the parts of the layer not. struck by light are removed with running water, and, after drying with hot air, the bared copper surface is etched with an iron-3-chloride solution having a gravity of 40 B. A printing plate suitable for intaglio printing is thus obtained. I

Instead of polyvinyl alcohol, a dispersion of polyvinyl acetate in dibutyl phthalate may be used.

Example III The procedure described in Example 11 is followed, using, instead of the support mentioned in Example II, a copper foil of 30 to 70p thickness laminatedto a dielectric plastic foil. After exposure, under a photographic negative of a wiring system, the areas not struck by light during exposure are removed by means of running water, the

4 ness, equally good results being obtained. In this way, elements for use in the manufacture of electrical apparatus are obtained.

Example IV One part by weight of the diazonium chloride of p-aminodiphenylamine and 2 parts by weight of a 40 percent formaldehyde solution are introduced, with stirring, into parts by volume of an aqueous emulsion consisting of polyvinyl alcohol, polyvinyl acetate, and dibutyl phthalate. The now light-sensitive emulsion is poured into a grooved scraper, which may be made of metal or plastic material, andapplied to a fabric drawn tautly over a frame and consisting of e.g. a polyamide, such as polye-amino-caprolactam, nylon, metal gauze, glass fiber, polyester, or natural silk. The coated fabric is then thoroughly dried with hot air and exposed under a diapositive in a vacuum frame. After removal of the areas not struck by light during exposure, by rinsing with water, the coated fabric is again dried. A screen printing stencil is thus obtained which is thoroughly hardened and has excellent sharpness of edges of the stencil, as well as of the prints produced therefrom.

Instead of 1 part by weight of the diazonium chloride of p-amino-diphenylamine there may be used, e.g., a mixture of 0.5 part by weight of the diazonium chloride and 0.5 part by weight of the diazonium sulfate of p-aminodiphenylamine.

The emulsion used in this example is prepared as follows: 100 part by weight of polyvinyl alcohol (Mowiol No. 30-88) in 580 parts by volume of distilled water are heated on a steam bath for 6 to 8 hours, with mechanical stirring. After the mixture has cooled to room temperature, 100 parts by weight of dibutyl phthalate are added, with mechanical stirring, and, after 15 minutes, a dispersion of 600 parts by weight of pulverized polyvinyl acetate (Vinnapas D-SO or Vinnapas H-60) in 900 parts by volume of distilled water is introduced.

Example V The method described in Example IV is followed, but instead of the emulsion of polyvinyl alcohol, polyvinyl acetate, and dibutyl phthalate, there is used an emulsion consisting of polyvinyl acetate and dibutyl phthalate only. An excellent stencil for screen printing is thus obtained which has very sharp edges of the stencil as well as of the prints produced therefrom.

Example VI The method described in Example IV is followed using, instead of 1 part by weight of the diazonium chloride of p-aminodiphenylamine and 2 parts by weight of formaldehyde (corresponding to 5 parts by volume of a 40 per cent formalin solution), 1.3 parts by weight of the condensation product of 4-diazonium phenlyamine and formaldehyde, in the form of the zinc chloride double salt, and 2 parts by weight of formaldehyde (corresponding to 5 parts by volume of a 40 percent formalin solution). A screen printing stencil is thus obtained which shows an outstanding degree of hardening, while a screen printing stencil prepared with the same amount of the Zinc chloride complex, but without the addition of 5 parts by volume of 40 percent formalin solution, is insufliciently tanned.

Example VII The method described in Example IV is followed using, however, instead of the emulsion of polyvinyl alcohol, polyvinyl acetate, and dibutyl phthalate, an emulsion in which the polyvinyl alcohol was replaced by an 8 to 10 percent aqueous solution of an epoxy resin (Polyox, watersoluble resin of Union Carbide International Company, New York city, N.Y., U.S.A.) A stencil is thus obtained which is very suitable for screen printing and which excels in sharpness of edge of the stencil as well as of the prints produced therewith.

Instead of '1 part by weight of the dinzonium chloride, the same amount of the diazo borofiuoride of p-aminodiphenylamine may be used with good results.

Example VIII The method described in Example IV is followed, using, instead of the emulsion of polyvinyl alcohol, polyvinyl acetate, and dibutyl phthalate, an emulsion in which polyvinyl alcohol was replaced by a percent solution of the sodium salt of carboxymethylcellulose. An excellent screen printing stencil is thus obtained which has very sharp edges of the stencil as well as the prints produced therewith.

Instead of 1 part by weight of the diazonium chloride, the same amount of the diazonium sulfate of p-aminodiphenylamine may be used with good results.

Example IX The method described in Example IV is followed, but instead of 2 parts by weight of formaldehyde, 2 parts by weight of furfural are used. A screen printing stencil is obtained which is excellently hardened and has extremely sharp contours of the stencil as well asof the prints produced therewith.

Instead of 2 parts by weight of furfural, the same amounts by weight of acetaldehyde, chloroacetaldehyde, glyoxal, glutardialdehyde, butyror isobutyraldehyde, propionaldehyde, isovaleraldehyde, or crotonaldehyde may be used, with equally good results.

Example X The method described in Example IV is followed, using, instead of 2 parts by weight of formaldehyde, 2 parts by weight of cinnamaldehyde. A screen printing stencil is thus obtained which is well hardened and in which the stencil as well as the prints made from it have excellently sharp edges.

Instead of 2 parts by weight of cinnamaldehyde, there may be used, with good results, the same amounts of pyridine-4-aldehyde, resorcylaldehyde, salicylaldeyhde, stilbenealdehyde, or terephthalaldehyde.

Example XI Example XII The method described in Example 1V is followed using, however, 1 part by weight of the diazonium chloride of lmonoethylamino-2-methyl-4-aminobenzene instead of 1 part by weight of the diazonium chloride of 4-aminp-diphenylamine. A very thoroughly hardened screen printing stencil is thus obtained.

Instead of 1 part by weight of the diazonium chloride of 1-monoethyl-amino-2-methyl-4-aminobenzene, there may be used 1 part by weight of either of the diazonium chlorides of 1-monoethylamine-3-carboxy-4-aminobenzene, l-monobutyl-amino-3-chloro-4-arn-inobenzene, or 1- monocyclohexylamino-3-methyl-4-aminobenzene.

Example XIII The method described in Example IVis followed, using, instead of 1 part by weight of the diazonium chloride of 4-arnino-diphenylamine, 1 part by weight of the diazonium chloride of l-mono-6-othoxybeuz thiazolylamino-4-bcnzene. A screen printing stencil is obtained which is thoroughly hardened.

Exalnple XIV 1 part by weight of the diazonium chloride of p-aminodiphenylamine and 5 parts by volume of a percent formaldehyde solution are added, with mechanical stirring, to 100 parts by volume of a 2 percent solution of hydroxyethyl cellulose in which 10 parts by weight of pulverized polyvinyl acetate were dispersed. The light sensitive emulsion thus obtained is poured into a grooved scraper of metal or plastic material and then applied to a fabric, e.g. a commercially available superpolyamide fabric or metal gauze, tautly drawn over a tentering frame. Subsequently, the coated fabric is dried at a temperature above 40 C. and then exposed under a diapositive in a vacuum frame. After removal of the areas not hardened by light during exposure, the partially decoated fabric is again dried at temperatures ranging from to C. A screen printing stencil is thus obtained which is thoroughly hardened and possesses very sharp edges, so that the prints obtained therefrom have very good contours.

Example XV The method described in Example IV is followed, using, however, instead of the aqueous emulsion of polyvinyl alcohol, polyvinyl acetate, and dibutyl phthalate, an emulsion containing 15 parts by weight of polyvinyl alcohol (Mowiol 5098), dissolved in parts by volume of water, and 7.5 parts by weight of dispersed polyvinyl alcohol (Mowiol 1/2 50-98). A screen printing stencil is thus obtained which is thoroughly hardened and has excellently sharp contours of the stencil as well as of the copies produced with the stencil.

It will be obvious to those skilled in the art that many' modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. Light sensitive material comprising a carrier and a colloid layer, the latter including at least one aldehyde and at least one diazo compound of an amine having the formula H N- N-Ri i the colloid layer includes a dyestuff.

4. Light sensitive material according to claim 1 in which the colloid layer includes a tiller.

5. Light sensitive material according to claim 1 in which the aldehyde is a lower aliphatic aldehyde.

6. Light sensitive material according to claim 1 in which the aldehyde is an aromatic aldehyde.

7. Light sensitive material according to claim 1 in which the aldehyde is a heterocyclic aldehyde.

8. Light sensitive material according to claim 1 in which the aldehyde is formaldehyde.

9. Light sensitive material according to claim 1 in which the aldehyde is selected from the group consisting of trichloroacctaldehyde, cinnarnaldehyde, pyridine-t-aldehyde,

resorcylaldehyde, sa-licylaldehyde, stilbenealdehyde and terephthalaldehyde.

10. Light sensitive material according to claim 1 in which the diazo compound is the diazonium chloride of p-aminodiphenylamine.

11. Light sensitive material according to claim 1 in which the diazo compound is the diazonium sulfate of 4-arninodiphenylamine.

12. Light sensitive material according to claim 1 in which the diazo compound i a condensation product of 4-diazonium phenylamine and formaldehyde in the form of the zinc chloride double salt.

13. Light sensitive material according to claim 1 in which the diazo compound is the diazonium chloride of 1-monoethyl-amino-2-methyl-4-aminobenzene.

14. Light sensitive material according to claim 1 in which the diazo compound is selected from the group consisting of the diazonium chlorides of l-monoethylamine 3 carboxy-4-aminobenzene, l-monobutylamino-3- chloro-4-aminobenzene and 1-monocyclohexyl-arnino-3- methyl-4-aminobenzene.

15. A process for developing light sensitive material comprising exposing a supported colloid layer to a light image and removing from the support those portions of the colloid layer which were not struck by light by treatment with a solvent, the colloid layer including at least one aldehyde and at least one diazo compound of an amine having the formula in which R is selected from the group consisting of alkyl, aryl, aralkyl, cycloalkyl and heterocyclic groups, R is selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, nitro, and carboxyl groups, and n is an integer from 1 to 2.

'16. A process according to claim in which the carrier is highly porous.

'17. A process according to claim 15 in which the carrier is imporous.

18. A process according to claim 15 in which the colloid layer includes a dyestuif.

"19. A process according to claim 15 in which the colloid layer includes a filler.

20. Aprocess according to claim 15in which the,

aldehyde is a lower aliphatic aldehyde.

21. A process according to claim 15 in aldehyde is an aromatic aldehyde.

22. A process according to claim 15 in aldehyde is a heterocyclic aldehyde.

23. A process according to claim 15 in aldehyde is formaldehyde.

24. A process according to claim 15 in which the aldehyde is selected from the group consisting of trichloroacetaldehyde, cinnamaldehyde, pyridine-4-aldehyde, resorcylaldehyde, salicylaldehyde, stilhenealdehyd: and terephthalaldehyde.

25. A process according to claim 15 in which the diazo compound is the diazonium chloride of p-arninodiphenylamine.

26. A process according to claim 15 in which the diazo compound is the diazonium sulfate of 4-aminodiphenylamine.

27. A process according to claim 15 in which the which the which the which the diazo compound is a condensation product of 4-diazoniumphcnylamine and fornmldchydc in the form of the zinc chloride double salt.

28. A process according to claim 15 in which the diazo compound is the diazonium chloride of lmonoethyl-amino-2-methyl-4-aminobenzene.

29. A process according to claim 15 in which the diazo compound is selected from the group consisting of the diazonium chlorides of 1-monoethylamine-3-carboxy- 4-aminobenzene, l-monobutylamino 3-chloro 4-aminobenzene and l-monocyclohexyl-amino-3-rnethyl-4-amino benzene.

30. A process according to claim 15 in which the solvent is water.

31. Light sensitive material comprising a carrier and a colloid layer, the latter including formaldehyde and a condensation product of an aldehyde and a diazo compound of an amine having the formula in which R is selected from the group consisting of alkyl, aryl, aralkyl, cycloalkyl and heterocyclic groups, R is selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, nitro, and carboxyl groups, and n is an integer from 1 to 2.

32. Light ,sensitive material according to claim 31 in which the condensation product is of 4-diazonium phenylamine and formaldehyde, in the form of the zinc chloride double salt.

33. A process for developing light sensitive material comprising exposing a supported colloid layer to a light image and removing from the support those portions of the colloid layer which were not struck by light by treatment with a solvent, the colloid layer including formaldehyde and a condensation product of an aldehyde and a diazo compound of an amine having the formula in which R is selected from the group consisting of alkyl, aryl, aralkyl, cycloalkyl and heterocyclic groups, R is selected from the group consisting of hydrogen, halogen, alkyl, alkoxy, nitro, and carboxyl groups, and n is an integer from 1 to 2.

54. A process according to claim 33 in which the condensation product is of 4-diazonium phenylarnine and formaldehyde, in the form of the zinc chloride double salt.

References Cited by the Examiner UNITED STATES PATENTS 2,063,631 12/36 Schmidt et al. 969l X 2,679,498 5/54 Seven et al. 96-33 X 3,012,886 12/61 Lerner 96-33 3,029,146 4/62 Schmidt et al. 96-33 NORMAN G. TORCHIN, Primary Examiner. 

1. LIGHT SENSITIVE MATERIAL COMPRISING A CARRIER AND A COLLOID LAYER, THE LATTER INCLUDING AT LEAST ONE ALDEHYDE AND AT LEAST ONE DIAZO COMPOUND OF AN AMINE HAVING THE FORMULA 